kilowatt hour vs kW-hr

kilowatt hour and kW-hr both are nouns.

Word	Noun	Adjective	Verb	Adverb
kilowatt hour	Yes	No	No	No
kW-hr	Yes	No	No	No

As nouns, kilowatt hour and kW-hr are synonyms defined as:

kilowatt hour and kW-hr: a unit of energy equal to the work done by a power of 1000 watts operating for one hour

Other synonyms of kilowatt hour include B.T.U., Board of Trade unit.

kilowatt hour (noun)	kW-hr (noun)
a unit of energy equal to the work done by a power of 1000 watts operating for one hour	a unit of energy equal to the work done by a power of 1000 watts operating for one hour